cluster: add option to specify busybox repository

pkg/apis/etcd/v1beta2/cluster.go

@@ -143,6 +143,11 @@ type PodPolicy struct {
 	// etcd cluster.
 	// The "etcd.version" annotation is reserved for the internal use of the etcd operator.
 	Annotations map[string]string `json:"annotations,omitempty"`
+
+	// busybox init container image. default is busybox:1.28.0-glibc
+	// busybox:latest uses uclibc which contains a bug that sometimes prevents name resolution
+	// More info: https://github.com/docker-library/busybox/issues/27
+	BusyboxImage string `json:"busyboxImage,omitempty"`
 }
 
 // TODO: move this to initializer

pkg/util/k8sutil/k8sutil.go

@@ -63,6 +63,8 @@ const (
 
 	defaultKubeAPIRequestTimeout = 30 * time.Second
 
+	defaultBusyboxImage = "busybox:1.28.0-glibc"
+
 	// AnnotationScope annotation name for defining instance scope. Used for specifing cluster wide clusters.
 	AnnotationScope = "etcd.database.coreos.com/scope"
 	//AnnotationClusterWide annotation value for cluster wide clusters.
@@ -134,6 +136,14 @@ func ImageName(repo, version string) string {
 	return fmt.Sprintf("%s:v%v", repo, version)
 }
 
+// imageNameBusybox returns the default image for busybox init container, or the image specified in the PodPolicy
+func imageNameBusybox(policy *api.PodPolicy) string {
+	if policy != nil && len(policy.BusyboxImage) > 0 {
+		return policy.BusyboxImage
+	}
+	return defaultBusyboxImage
+}
+
 func PodWithNodeSelector(p *v1.Pod, ns map[string]string) *v1.Pod {
 	p.Spec.NodeSelector = ns
 	return p
@@ -355,7 +365,8 @@ func newEtcdPod(m *etcdutil.Member, initialCluster []string, clusterName, state,
 			InitContainers: []v1.Container{{
 				// busybox:latest uses uclibc which contains a bug that sometimes prevents name resolution
 				// More info: https://github.com/docker-library/busybox/issues/27
-				Image: "busybox:1.28.0-glibc",
+				//Image default: "busybox:1.28.0-glibc",
+				Image: imageNameBusybox(cs.Pod),
 				Name:  "check-dns",
 				// In etcd 3.2, TLS listener will do a reverse-DNS lookup for pod IP -> hostname.
 				// If DNS entry is not warmed up, it will return empty result and peer connection will be rejected.

pkg/util/k8sutil/k8sutils_test.go

@@ -0,0 +1,49 @@
+// Copyright 2017 The etcd-operator Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package k8sutil
+
+import (
+	"testing"
+
+	api "github.com/coreos/etcd-operator/pkg/apis/etcd/v1beta2"
+)
+
+func TestDefaultBusyboxImageName(t *testing.T) {
+	policy := &api.PodPolicy{}
+	image := imageNameBusybox(policy)
+	expected := defaultBusyboxImage
+	if image != expected {
+		t.Errorf("expect image=%s, get=%s", expected, image)
+	}
+}
+
+func TestDefaultNilBusyboxImageName(t *testing.T) {
+	image := imageNameBusybox(nil)
+	expected := defaultBusyboxImage
+	if image != expected {
+		t.Errorf("expect image=%s, get=%s", expected, image)
+	}
+}
+
+func TestSetBusyboxImageName(t *testing.T) {
+	policy := &api.PodPolicy{
+		BusyboxImage: "myRepo/busybox:1.3.2",
+	}
+	image := imageNameBusybox(policy)
+	expected := "myRepo/busybox:1.3.2"
+	if image != expected {
+		t.Errorf("expect image=%s, get=%s", expected, image)
+	}
+}